Add Quark script showcase of detecting CWE-359

[JerryTasi]

Detect CWE-359 in Android Application

This scenario aims to demonstrate the detection of the Exposure of Private Personal Information to an Unauthorized Actor vulnerability.

CWE-359: Exposure of Private Personal Information to an Unauthorized Actor

We analyze the definition of CWE-359 and identify its characteristics.

See CWE-359 for more details.

Code of CWE-359 in ovaa.apk

We use the ovaa.apk sample to explain the vulnerability code of CWE-359.

CWE-359 Detection Process Using Quark Script API

Let’s use the above APIs to show how the Quark script finds this vulnerability.

To begin with, we create a detection rule named accessFileWithUnsafeUriPath.json to identify behavior that accesses a file with an unsafe path from Uri.

Next, we use API methodInstance.methodCaller to retrieve the name of the caller that has this behavior.

Then, we use API quarkResultInstance.isHardcoded(argument) to check if the file path is hardcoded into the APK. If not, the file path is likely from external input.

After that, we use API getProviders(samplePath) and providerInstance.isExported() to check if there is any exported provider that matches the caller class name. If yes, any external application can access the behavior.

Finally, we use API quarkResultInstance.findMethodInCaller(callerMethod, targetMethod) to search for any APIs in the caller method that are used to match strings.

If NO API is found, that implies the APK does not neutralize special elements within the argument, possibly resulting in a CWE-359 vulnerability.

Quark Script: CWE-359.py

from quark.script import Rule, runQuarkAnalysis, getProviders

SAMPLE_PATH = "ovaa.apk"
RULE_PATH = "accessFileWithUnsafeUriPath.json"

STRING_MATCHING_API = [
    ["Ljava/lang/String;", "contains", "(Ljava/lang/CharSequence)Z"],
    ["Ljava/lang/String;", "indexOf", "(I)I"],
    ["Ljava/lang/String;", "indexOf", "(Ljava/lang/String;)I"],
    ["Ljava/lang/String;", "matches", "(Ljava/lang/String;)Z"],
    [
        "Ljava/lang/String;",
        "replaceAll",
        "(Ljava/lang/String; Ljava/lang/String;)Ljava/lang/String;",
    ],
]

ruleInstance = Rule(RULE_PATH)
quarkResult = runQuarkAnalysis(SAMPLE_PATH, ruleInstance)

exportedProviders = [
    str(provider)
    for provider in getProviders(SAMPLE_PATH)
    if provider.isExported()
]

for behavior in quarkResult.behaviorOccurList:
    caller = behavior.methodCaller
    classNameInJavaFormat = caller.className.replace("/", ".")[1:-1]
    filePath = behavior.secondAPI.getArguments()[2]

    if quarkResult.isHardcoded(filePath):
        continue

    if classNameInJavaFormat not in exportedProviders:
        continue

    if not any(
        quarkResult.findMethodInCaller(caller, api)
        for api in STRING_MATCHING_API
    ):
        print(f"CWE-359 is detected in method, {caller.fullName}")

Quark Rule: accessFileWithUnsafeUriPath.json

{
    "crime": "Access a File with an unsafe path from Uri",
    "permission": [],
    "api": [
        {
            "class": "Landroid/net/Uri;",
            "method": "getLastPathSegment",
            "descriptor": "()Ljava/lang/String;"
        },
        {
            "class": "Ljava/io/File;",
            "method": "<init>",
            "descriptor": "(Ljava/io/File;Ljava/lang/String;)V"
        }
    ],
    "score": 1,
    "label": []
}

Quark Script Result

$ python3 CWE-359.py
CWE-359 is detected in method, Loversecured/ovaa/providers/TheftOverwriteProvider; openFile (Landroid/net/Uri; Ljava/lang/String;)Landroid/os/ParcelFileDescriptor;

[zinwang]

LGTM!